# Table of Contents * [Installation](#installation) * [Preliminaries](#preliminaries) * [Installing lnd](#installing-lnd) * [Available Backend Operating Modes](#available-backend-operating-modes) * [btcd Options](#btcd-options) * [Neutrino Options](#neutrino-options) * [Bitcoind Options](#bitcoind-options) * [Using btcd](#using-btcd) * [Installing btcd](#installing-btcd) * [Starting btcd](#starting-btcd) * [Running lnd using the btcd backend](#running-lnd-using-the-btcd-backend) * [Using Neutrino](#using-neutrino) * [Using bitcoind or litecoind](#using-bitcoind-or-litecoind) * [Creating a Wallet](#creating-a-wallet) * [Macaroons](#macaroons) * [Network Reachability](#network-reachability) * [Simnet vs. Testnet Development](#simnet-vs-testnet-development) * [Creating an lnd.conf (Optional)](#creating-an-lndconf-optional) # Installation ### Preliminaries In order to work with [`lnd`](https://github.com/lightningnetwork/lnd), the following build dependencies are required: * **Go:** `lnd` is written in Go. To install, run one of the following commands: **Note**: The minimum version of Go supported is Go 1.13. We recommend that users use the latest version of Go, which at the time of writing is [`1.13`](https://blog.golang.org/go1.13). On Linux: (x86-64) ``` wget https://dl.google.com/go/go1.13.linux-amd64.tar.gz sha256sum go1.13.linux-amd64.tar.gz | awk -F " " '{ print $1 }' ``` The final output of the command above should be `68a2297eb099d1a76097905a2ce334e3155004ec08cdea85f24527be3c48e856`. If it isn't, then the target REPO HAS BEEN MODIFIED, and you shouldn't install this version of Go. If it matches, then proceed to install Go: ``` tar -C /usr/local -xzf go1.13.linux-amd64.tar.gz export PATH=$PATH:/usr/local/go/bin ``` (ARMv6) ``` wget https://dl.google.com/go/go1.13.linux-armv6l.tar.gz sha256sum go1.13.linux-armv6l.tar.gz | awk -F " " '{ print $1 }' ``` The final output of the command above should be `931906d67cae1222f501e7be26e0ee73ba89420be0c4591925901cb9a4e156f0`. If it isn't, then the target REPO HAS BEEN MODIFIED, and you shouldn't install this version of Go. If it matches, then proceed to install Go: ``` tar -C /usr/local -xzf go1.13.linux-armv6l.tar.gz export PATH=$PATH:/usr/local/go/bin ``` On Mac OS X: ``` brew install go@1.13 ``` On FreeBSD: ``` pkg install go ``` Alternatively, one can download the pre-compiled binaries hosted on the [Golang download page](https://golang.org/dl/). If one seeks to install from source, then more detailed installation instructions can be found [here](https://golang.org/doc/install). At this point, you should set your `$GOPATH` environment variable, which represents the path to your workspace. By default, `$GOPATH` is set to `~/go`. You will also need to add `$GOPATH/bin` to your `PATH`. This ensures that your shell will be able to detect the binaries you install. ```bash export GOPATH=~/gocode export PATH=$PATH:$GOPATH/bin ``` We recommend placing the above in your .bashrc or in a setup script so that you can avoid typing this every time you open a new terminal window. * **Go modules:** This project uses [Go modules](https://github.com/golang/go/wiki/Modules) to manage dependencies as well as to provide *reproducible builds*. Usage of Go modules (with Go 1.12) means that you no longer need to clone `lnd` into your `$GOPATH` for development purposes. Instead, your `lnd` repo can now live anywhere! ### Installing lnd With the preliminary steps completed, to install `lnd`, `lncli`, and all related dependencies run the following commands: ``` go get -d github.com/lightningnetwork/lnd cd $GOPATH/src/github.com/lightningnetwork/lnd make && make install ``` **NOTE**: Our instructions still use the `$GOPATH` directory from prior versions of Go, but with Go 1.12, it's now possible for `lnd` to live _anywhere_ on your file system. For Windows WSL users, make will need to be referenced directly via /usr/bin/make/, or alternatively by wrapping quotation marks around make, like so: ``` /usr/bin/make && /usr/bin/make install "make" && "make" install ``` On FreeBSD, use gmake instead of make. Alternatively, if one doesn't wish to use `make`, then the `go` commands can be used directly: ``` GO111MODULE=on go install -v ./... ``` **Updating** To update your version of `lnd` to the latest version run the following commands: ``` cd $GOPATH/src/github.com/lightningnetwork/lnd git pull make clean && make && make install ``` On FreeBSD, use gmake instead of make. Alternatively, if one doesn't wish to use `make`, then the `go` commands can be used directly: ``` cd $GOPATH/src/github.com/lightningnetwork/lnd git pull GO111MODULE=on go install -v ./... ``` **Tests** To check that `lnd` was installed properly run the following command: ``` make check ``` This command requires `bitcoind` (almost any version should do) to be available in the system's `$PATH` variable. Otherwise some of the tests will fail. # Available Backend Operating Modes In order to run, `lnd` requires, that the user specify a chain backend. At the time of writing of this document, there are three available chain backends: `btcd`, `neutrino`, `bitcoind`. All but neutrino (atm) can run on mainnet with an out of the box `lnd` instance. We don't require `--txindex` when running with `bitcoind` or `btcd` but activating the `txindex` will generally make `lnd` run faster. **NOTE: WE DO NOT FULLY SUPPORT PRUNED OPERATING MODES FOR FULL NODES.** It's possible to run a node in a pruned mode and have it serve lnd, however one must take care to ensure that `lnd` has all blocks on disk since the birth of the wallet, and the age of the earliest channels (which were created around March 2018). The set of arguments for each of the backend modes is as follows: ## btcd Options ``` btcd: --btcd.dir= The base directory that contains the node's data, logs, configuration file, etc. (default: /Users/roasbeef/Library/Application Support/Btcd) --btcd.rpchost= The daemon's rpc listening address. If a port is omitted, then the default port for the selected chain parameters will be used. (default: localhost) --btcd.rpcuser= Username for RPC connections --btcd.rpcpass= Password for RPC connections --btcd.rpccert= File containing the daemon's certificate file (default: /Users/roasbeef/Library/Application Support/Btcd/rpc.cert) --btcd.rawrpccert= The raw bytes of the daemon's PEM-encoded certificate chain which will be used to authenticate the RPC connection. ``` ## Neutrino Options ``` neutrino: -a, --neutrino.addpeer= Add a peer to connect with at startup --neutrino.connect= Connect only to the specified peers at startup --neutrino.maxpeers= Max number of inbound and outbound peers --neutrino.banduration= How long to ban misbehaving peers. Valid time units are {s, m, h}. Minimum 1 second --neutrino.banthreshold= Maximum allowed ban score before disconnecting and banning misbehaving peers. ``` ## Bitcoind Options ``` bitcoind: --bitcoind.dir= The base directory that contains the node's data, logs, configuration file, etc. (default: /Users/roasbeef/Library/Application Support/Bitcoin) --bitcoind.rpchost= The daemon's rpc listening address. If a port is omitted, then the default port for the selected chain parameters will be used. (default: localhost) --bitcoind.rpcuser= Username for RPC connections --bitcoind.rpcpass= Password for RPC connections --bitcoind.zmqpubrawblock= The address listening for ZMQ connections to deliver raw block notifications --bitcoind.zmqpubrawtx= The address listening for ZMQ connections to deliver raw transaction notifications --bitcoind.estimatemode= The fee estimate mode. Must be either "ECONOMICAL" or "CONSERVATIVE". (default: CONSERVATIVE) ``` ## Using btcd ### Installing btcd On FreeBSD, use gmake instead of make. To install btcd, run the following commands: Install **btcd**: ``` make btcd ``` Alternatively, you can install [`btcd` directly from its repo](https://github.com/btcsuite/btcd). ### Starting btcd Running the following command will create `rpc.cert` and default `btcd.conf`. ``` btcd --testnet --rpcuser=REPLACEME --rpcpass=REPLACEME ``` If you want to use `lnd` on testnet, `btcd` needs to first fully sync the testnet blockchain. Depending on your hardware, this may take up to a few hours. Note that adding `--txindex` is optional, as it will take longer to sync the node, but then `lnd` will generally operate faster as it can hit the index directly, rather than scanning blocks or BIP 158 filters for relevant items. (NOTE: It may take several minutes to find segwit-enabled peers.) While `btcd` is syncing you can check on its progress using btcd's `getinfo` RPC command: ``` btcctl --testnet --rpcuser=REPLACEME --rpcpass=REPLACEME getinfo { "version": 120000, "protocolversion": 70002, "blocks": 1114996, "timeoffset": 0, "connections": 7, "proxy": "", "difficulty": 422570.58270815, "testnet": true, "relayfee": 0.00001, "errors": "" } ``` Additionally, you can monitor btcd's logs to track its syncing progress in real time. You can test your `btcd` node's connectivity using the `getpeerinfo` command: ``` btcctl --testnet --rpcuser=REPLACEME --rpcpass=REPLACEME getpeerinfo | more ``` ### Running lnd using the btcd backend If you are on testnet, run this command after `btcd` has finished syncing. Otherwise, replace `--bitcoin.testnet` with `--bitcoin.simnet`. If you are installing `lnd` in preparation for the [tutorial](https://dev.lightning.community/tutorial), you may skip this step. ``` lnd --bitcoin.active --bitcoin.testnet --debuglevel=debug --btcd.rpcuser=kek --btcd.rpcpass=kek --externalip=X.X.X.X ``` ## Using Neutrino In order to run `lnd` in its light client mode, you'll need to locate a full-node which is capable of serving this new light client mode. `lnd` uses [BIP 157](https://github.com/bitcoin/bips/blob/master/bip-0157.mediawiki) and [BIP 158](https://github.com/bitcoin/bips/blob/master/bip-0158.mediawiki) for its light client mode. A public instance of such a node can be found at `faucet.lightning.community`. To run lnd in neutrino mode, run `lnd` with the following arguments, (swapping in `--bitcoin.simnet` if needed), and also your own `btcd` node if available: ``` lnd --bitcoin.active --bitcoin.testnet --debuglevel=debug --bitcoin.node=neutrino --neutrino.connect=faucet.lightning.community ``` ## Using bitcoind or litecoind The configuration for bitcoind and litecoind are nearly identical, the following steps can be mirrored with loss of generality to enable a litecoind backend. Setup will be described in regards to `bitcoind`, but note that `lnd` uses a distinct `litecoin.node=litecoind` argument and analogous subconfigurations prefixed by `litecoind`. Note that adding `--txindex` is optional, as it will take longer to sync the node, but then `lnd` will generally operate faster as it can hit the index directly, rather than scanning blocks or BIP 158 filters for relevant items. To configure your bitcoind backend for use with lnd, first complete and verify the following: - Since `lnd` uses [ZeroMQ](https://github.com/bitcoin/bitcoin/blob/master/doc/zmq.md) to interface with `bitcoind`, *your `bitcoind` installation must be compiled with ZMQ*. Note that if you installed `bitcoind` from source and ZMQ was not present, then ZMQ support will be disabled, and `lnd` will quit on a `connection refused` error. If you installed `bitcoind` via Homebrew in the past ZMQ may not be included ([this has now been fixed](https://github.com/Homebrew/homebrew-core/pull/23088) in the latest Homebrew recipe for bitcoin) - Configure the `bitcoind` instance for ZMQ with `--zmqpubrawblock` and `--zmqpubrawtx`. These options must each use their own unique address in order to provide a reliable delivery of notifications (e.g. `--zmqpubrawblock=tcp://127.0.0.1:28332` and `--zmqpubrawtx=tcp://127.0.0.1:28333`). - Start `bitcoind` running against testnet, and let it complete a full sync with the testnet chain (alternatively, use `--bitcoind.regtest` instead). Here's a sample `bitcoin.conf` for use with lnd: ``` testnet=1 server=1 daemon=1 zmqpubrawblock=tcp://127.0.0.1:28332 zmqpubrawtx=tcp://127.0.0.1:28333 ``` Once all of the above is complete, and you've confirmed `bitcoind` is fully updated with the latest blocks on testnet, run the command below to launch `lnd` with `bitcoind` as your backend (as with `bitcoind`, you can create an `lnd.conf` to save these options, more info on that is described further below): ``` lnd --bitcoin.active --bitcoin.testnet --debuglevel=debug --bitcoin.node=bitcoind --bitcoind.rpcuser=REPLACEME --bitcoind.rpcpass=REPLACEME --bitcoind.zmqpubrawblock=tcp://127.0.0.1:28332 --bitcoind.zmqpubrawtx=tcp://127.0.0.1:28333 --externalip=X.X.X.X ``` *NOTE:* - The auth parameters `rpcuser` and `rpcpass` parameters can typically be determined by `lnd` for a `bitcoind` instance running under the same user, including when using cookie auth. In this case, you can exclude them from the `lnd` options entirely. - If you DO choose to explicitly pass the auth parameters in your `lnd.conf` or command line options for `lnd` (`bitcoind.rpcuser` and `bitcoind.rpcpass` as shown in example command above), you must also specify the `bitcoind.zmqpubrawblock` and `bitcoind.zmqpubrawtx` options. Otherwise, `lnd` will attempt to get the configuration from your `bitcoin.conf`. - You must ensure the same addresses are used for the `bitcoind.zmqpubrawblock` and `bitcoind.zmqpubrawtx` options passed to `lnd` as for the `zmqpubrawblock` and `zmqpubrawtx` passed in the `bitcoind` options respectively. - When running lnd and bitcoind on the same Windows machine, ensure you use 127.0.0.1, not localhost, for all configuration options that require a TCP/IP host address. If you use "localhost" as the host name, you may see extremely slow inter-process-communication between lnd and the bitcoind backend. If lnd is experiencing this issue, you'll see "Waiting for chain backend to finish sync, start_height=XXXXXX" as the last entry in the console or log output, and lnd will appear to hang. Normal lnd output will quickly show multiple messages like this as lnd consumes blocks from bitcoind. - Don't connect more than two or three instances of `lnd` to `bitcoind`. With the default `bitcoind` settings, having more than one instance of `lnd`, or `lnd` plus any application that consumes the RPC could cause `lnd` to miss crucial updates from the backend. - The default fee estimate mode in `bitcoind` is CONSERVATIVE. You can set `bitcoind.estimatemode=ECONOMICAL` to change it into ECONOMICAL. Futhermore, if you start `bitcoind` in `regtest`, this configuration won't take any effect. # Creating a wallet If `lnd` is being run for the first time, create a new wallet with: ``` lncli create ``` This will prompt for a wallet password, and optionally a cipher seed passphrase. `lnd` will then print a 24 word cipher seed mnemonic, which can be used to recover the wallet in case of data loss. The user should write this down and keep in a safe place. # Macaroons `lnd`'s authentication system is called **macaroons**, which are decentralized bearer credentials allowing for delegation, attenuation, and other cool features. You can learn more about them in Alex Akselrod's [writeup on Github](https://github.com/lightningnetwork/lnd/issues/20). Running `lnd` for the first time will by default generate the `admin.macaroon`, `read_only.macaroon`, and `macaroons.db` files that are used to authenticate into `lnd`. They will be stored in the network directory (default: `lnddir/data/chain/bitcoin/mainnet`) so that it's possible to use a distinct password for mainnet, testnet, simnet, etc. Note that if you specified an alternative data directory (via the `--datadir` argument), you will have to additionally pass the updated location of the `admin.macaroon` file into `lncli` using the `--macaroonpath` argument. To disable macaroons for testing, pass the `--no-macaroons` flag into *both* `lnd` and `lncli`. # Network Reachability If you'd like to signal to other nodes on the network that you'll accept incoming channels (as peers need to connect inbound to initiate a channel funding workflow), then the `--externalip` flag should be set to your publicly reachable IP address. # Simnet vs. Testnet Development If you are doing local development, such as for the tutorial, you'll want to start both `btcd` and `lnd` in the `simnet` mode. Simnet is similar to regtest in that you'll be able to instantly mine blocks as needed to test `lnd` locally. In order to start either daemon in the `simnet` mode use `simnet` instead of `testnet`, adding the `--bitcoin.simnet` flag instead of the `--bitcoin.testnet` flag. Another relevant command line flag for local testing of new `lnd` developments is the `--debughtlc` flag. When starting `lnd` with this flag, it'll be able to automatically settle a special type of HTLC sent to it. This means that you won't need to manually insert invoices in order to test payment connectivity. To send this "special" HTLC type, include the `--debugsend` command at the end of your `sendpayment` commands. There are currently two primary ways to run `lnd`: one requires a local `btcd` instance with the RPC service exposed, and the other uses a fully integrated light client powered by [neutrino](https://github.com/lightninglabs/neutrino). # Creating an lnd.conf (Optional) Optionally, if you'd like to have a persistent configuration between `lnd` launches, allowing you to simply type `lnd --bitcoin.testnet --bitcoin.active` at the command line, you can create an `lnd.conf`. **On MacOS, located at:** `/Users/[username]/Library/Application Support/Lnd/lnd.conf` **On Linux, located at:** `~/.lnd/lnd.conf` Here's a sample `lnd.conf` for `btcd` to get you started: ``` [Application Options] debuglevel=trace maxpendingchannels=10 [Bitcoin] bitcoin.active=1 ``` Notice the `[Bitcoin]` section. This section houses the parameters for the Bitcoin chain. `lnd` also supports Litecoin testnet4 (but not both BTC and LTC at the same time), so when working with Litecoin be sure to set to parameters for Litecoin accordingly. See a more detailed sample config file available [here](https://github.com/lightningnetwork/lnd/blob/master/sample-lnd.conf) and explore the other sections for node configuration, including `[Btcd]`, `[Bitcoind]`, `[Neutrino]`, `[Ltcd]`, and `[Litecoind]` depending on which chain and node type you're using.